A pyrroloquinoline quinone-dependent β-D glucose dehydrogenase (EC1.1.199, PQQGDH) is conjugated with a coenzyme, pyrrolo-quinoline quinone (PQQ) to catalyze a reaction of oxidizing β-D glucose to produce glucono-lactone. With this property, PQQGDH is used for determining an amount of glucose in a clinical test, a food analysis, monitoring of a culture process, and the like.
As examples of PQQGDH reported in the past, a PQQGDH produced by Acinetobacter species L.M.D 79.41 strain and a modified PQQGDH thereof are known (for example, JP 2000-312588A, JP 2000-350588A, JP 2000-197888A, JP 2001-346587A, WO02-34919 (A1), and A-M Cleton-Jansen et al., Mol. Gen. Genet., 217, 430 (1989)). The substrate specificity of the PQQGDH produced by L.M.D 79.41 strain is low. For example, also with respect to maltose, the reactivity of the PQQGDH has a reactivity corresponding to about 90% of the reactivity with respect to glucose.